In general, semiconductor devices include a block shaped package body in which an IC chip is sealed and a large number of leads which project out from the opposing sides of the package body and are electrically connected to the IC chip. Various types of packages for semiconductor devices are known. As typical examples, mention may be made of SOP (small outline packages), QFP (quad flat packages), and PGA (pin grid array packages).
In recent years, progress has been made in making semiconductor devices higher in density. Along with this, the amount of heat generated in such devices has increased and therefore it is becoming difficult to sufficiently cool the semiconductor devices by radiation of heat from the package body itself. Therefore, heat radiating fin assemblies are being attached to the package body so as to enable efficient radiation of heat from the semiconductor devices. Usually, a heat radiating assembly is constructed of a support column which is designed to be affixed to the package body of a semiconductor device and a large number of fins which extend from the support column in the radial direction and are arranged at equal intervals along the axial direction of the support column.
In a high density semiconductor device, the pitch of the arrangement of the large number of leads projecting out from the opposing sides of the package body is extremely small, therefore if even one of the leads is slightly deformed, it becomes impossible to accurately mount the semiconductor device on the printed circuit board. Therefore, when transporting this type of semiconductor device, it is necessary to provide protection so that the leads of the semiconductor device do not come into contact with human hands or other objects.
In the past, use has been made of a protective carrier for holding individual semiconductor devices so as to prevent damage to the leads of the semiconductor device during shipment. Such protective carriers include a frame for accommodating the package body of the semiconductor device and a lock mechanism for preventing the package body from falling out of the accommodating frame. Further, at the inside edge of the frame of the protective carrier, a large number of fine grooves are formed at the same pitch as the pitch of arrangement of the leads, so that the leads are accommodated in the fine grooves at the same time as the package body is accommodated in the frame. During shipment, the protective carriers containing respective semiconductor devices are placed in a tray or other container. As long as the semiconductor device remains in the protective carrier, damage to the leads can be avoided.
However, a problem with the method of shipment of semiconductor devices discussed above is that the transport costs are too high. Such protective carriers have a complicated structure and therefore are relatively expensive. Further, a protective carrier is required for each semiconductor device to be shipped.
Another problem with the use of protective carriers is that when the semiconductor device is mounted on a printed circuit board, manual labor is involved in removing the semiconductor device from the protective carrier. The leads are easily damaged when the semiconductor device is removed from the protective carrier, so considerable care must be taken when removing the semiconductor device manually. On the other hand, an automatic extraction machine for automatically extracting the semiconductor devices from the protective carriers in an automatic procedure would be very expensive.
Japanese Unexamined Utility Model Publication (Kokai) No. 1-158949 discloses a transport carrier which is able to hold a number of semiconductor devices having heat radiating fin assemblies. In this transport carrier, use is made of the heat radiating fin assembly to hold the semiconductor device. As mentioned in detail in such publication, the transport carrier is comprised of an elongated box-shaped casing, which is disposed with its longitudinal axis extending in a horizontal direction. The upper edge of the front wall of the box-shaped casing is connecting to the top wall by hinges so the casing can be freely opened or closed.
However, it is difficult to automatically remove semiconductor devices from such box-shaped casings and to supply them to an automatic semiconductor device mounting machine. That is to say, the support columns of the heat radiating fin assemblies are not constrained, so the semiconductor devices accommodated in the box-shaped casing cannot all be given the same orientation. While it might be possible to develop an automatic extraction machine able to automatically extract semiconductor devices oriented in different directions and give them a predetermined orientation, considerable cost would be required for developing such an automatic extraction machine.